Model Comparison
Claude Opus 4.6 vs GPT-5.6 TerraWhich is better in 2026?
GPT-5.6 Terra significantly outperforms across most benchmarks. GPT-5.6 Terra is 1.8x cheaper per token.
Verdict: Claude Opus 4.6 vs GPT-5.6 Terra — which is better?
Claude Opus 4.6 (by Anthropic) and GPT-5.6 Terra (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Claude Opus 4.6 outperforms in 1 benchmarks (GDPval-AA), while GPT-5.6 Terra is better at 5 benchmarks (BrowseComp, GPQA, Graphwalks BFS >128k, MMMU-Pro, MRCR v2 (8-needle)). GPT-5.6 Terra significantly outperforms across most benchmarks.
On price, GPT-5.6 Terra is roughly 1.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Terra also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose Claude Opus 4.6 if…
- you want predictable pricing at $5.00/M input and $25.00/M output
Choose GPT-5.6 Terra if…
- you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
- cost matters — it's about 1.8x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
Claude Opus 4.6 outperforms in 1 benchmarks (GDPval-AA), while GPT-5.6 Terra is better at 5 benchmarks (BrowseComp, GPQA, Graphwalks BFS >128k, MMMU-Pro, MRCR v2 (8-needle)).
GPT-5.6 Terra significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.6 ($5.00/1M tokens) is 2.0x more expensive than GPT-5.6 Terra ($2.50/1M tokens).
For output processing, Claude Opus 4.6 ($25.00/1M tokens) is 1.7x more expensive than GPT-5.6 Terra ($15.00/1M tokens).
In conclusion, Claude Opus 4.6 is more expensive than GPT-5.6 Terra.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Terra accepts 1,050,000 input tokens compared to Claude Opus 4.6's 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Opus 4.6 and GPT-5.6 Terra support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 4.6
GPT-5.6 Terra
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Opus 4.6 was released on 2026-02-05, while GPT-5.6 Terra was released on 2026-07-09.
GPT-5.6 Terra is 5 months newer than Claude Opus 4.6.
Feb 5, 2026
5 months ago
Jul 9, 2026
1 weeks ago
5mo newerKnowledge Cutoff
When training data ends
GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Claude Opus 4.6's cutoff date is not specified.
We can confirm GPT-5.6 Terra's training data extends to 2026-02-16, but cannot make a direct comparison without Claude Opus 4.6's cutoff date.
—
Feb 2026
Provider Availability
Claude Opus 4.6 is available from Anthropic. GPT-5.6 Terra is available from OpenAI.
Claude Opus 4.6
GPT-5.6 Terra
Outputs Comparison
Key Takeaways
Claude Opus 4.6
View detailsAnthropic
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Claude Opus 4.6 and GPT-5.6 Terra side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Claude Opus 4.6 vs GPT-5.6 Terra.